Mobile communication system has been developed to provide an audio service by securing user's activity and mobility. The ongoing trend of the mobile communication system is to extend its service capability to a data service as well as the audio service. Currently, the development of the mobile communication system enables a high-speed data service. Yet, since a currently serviced mobile communication system causes resource shortage and fails in meeting user's request for a faster service, the demand for a further advanced mobile communication system is rising.
One of the most significant requirements for the next generation wireless access system is the capability of supporting the high data rate requisite. To this end, many on going efforts are made to research and develop various technologies including MIMO (multiple input multiple output), CoMP (cooperative multiple point transmission), relay and the like.
Moreover, in order to accommodate the skyrocketing wireless data requisite, the application of the heterogeneous network consisting of macro-pico or macro-femto cells is currently extended. In doing so, the pico cell or the femto cell is located within the macro cell. In this situation, a user equipment located on a boundary between overlapping cells faces a problem that signals transmitted from the overlapping cells mutually work as interference on each other.